There’s evidence you can will yourself to wake on time, too. Sleep scientists at Germany’s University of Lubeck asked 15 volunteers to sleep in their lab for three nights. One night, the group was told they’d be woken at 6 a.m., while on other nights the group was told they’d be woken at 9 a.m.. But the researchers lied-they woke the volunteers at 6 a.m anyway.
And the results were startling.
We wake up before our alarms quite precisely if we’re used to sleep and wake up at the same time. Quite interesting study.